Multilayer film, packaging material and package

Abstract

A multilayer film including a first outer layer containing 70 to 30% by mass of a propylene homopolymer (A) and 30 to 70% by mass of a propylene/ethylene random copolymer (B) having an ethylene content of 5% by mass or less, an inner layer containing a propylene/ethylene block copolymer (C) and an ethylene/propylene copolymer elastomer (D), and a second outer layer containing 70 to 30% by mass of the propylene homopolymer (A) and 30 to 70% by mass of the propylene/ethylene random copolymer (B) having an ethylene content of 5% by mass or less, in that order.

1 . A multilayer film comprising:
 a first outer layer containing 70 to 30% by mass of a propylene homopolymer (A) and 30 to 70% by mass of a propylene/ethylene random copolymer (B) having an ethylene content of 5% by mass or less;   an inner layer containing a propylene/ethylene block copolymer (C) and an ethylene/propylene copolymer elastomer (D); and   a second outer layer containing 70 to 30% by mass of the propylene homopolymer (A) and 30 to 70% by mass of the propylene/ethylene random copolymer (B) having an ethylene content of 5% by mass or less, in that order.   
     
     
         2 . The multilayer film according to  claim 1 , wherein a ratio Mw (EPR)/Mw (PP) of a weight-average molecular weight Mw (EPR) of an ethylene-propylene copolymer to a weight-average molecular weight Mw (PP) of a propylene polymer in the propylene/ethylene block copolymer (C) is 1.5 or less. 
     
     
         3 . The multilayer film according to  claim 1 , wherein the inner layer contains 90 to 50% by mass of the propylene/ethylene block copolymer (C) and 10 to 50% by mass of the ethylene/propylene copolymer elastomer (D). 
     
     
         4 . The multilayer film according to  claim 1 , wherein a total thickness of the first outer layer and the second outer layer is 16 to 42% based on a thickness of the multilayer film. 
     
     
         5 . The multilayer film according to  claim 1 , wherein a thickness of the inner layer is 20 μm or more. 
     
     
         6 . The multilayer film according to  claim 2 , wherein a thickness in a lamination direction of the ethylene-propylene copolymer present in the inner layer as a dispersing element is 1.5 μm or less. 
     
     
         7 . A packaging material comprising the multilayer film according to  claim 1 , and a base material. 
     
     
         8 . A package made from a packaging material according to  claim 7 .